Bernardino Telesio

Bernardino Telesio (1509–1588) belongs to a group of independent
philosophers of the late Renaissance who left the universities in order
to develop philosophical and scientific ideas beyond the restrictions
of the Aristotelian-scholastic tradition. Authors in the early modern
period referred to these philosophers as ‘novateurs’ and
‘modern’. In contrast to his successors Patrizzi and Campanella,
Telesio was a fervent critic of metaphysics and insisted on a purely
empiricist approach in natural philosophy—he thus became a forerunner
of early modern empiricism. He had a remarkable influence on Tommaso
Campanella, Giordano Bruno, Pierre Gassendi, Francis Bacon, Thomas
Hobbes and on freethinkers like Guillaume Lamy
and Giulio Cesare Vanini.

Bernardino Telesio was born at Cosenza in Calabria in 1509 as the
son of a noble and quite wealthy family. Having been educated by his
uncle Antonio Telesio, a humanist of note, he studied in Milan, Rome
and the famous university of Padua, which he left in 1535. There is no
evidence that Telesio gained a doctorate. Instead of undertaking a
university career, he spent several years in a Benedictine monastery
(1535–44) without taking oaths. Later he lived in the Neapolitan home
of Alfonso III Carafa, Duke of Nocera. In 1553 he married and settled
in Cosenza, becoming the dominant figure of the Accademia Cosentina,
which came to focus on natural philosophy under his tutelage. Telesio
never held a salaried position. After the death of his wife in 1561,
which marked the beginning of his financial difficulties, he seems to
have spent some time in Rome under the patronage of Pope Pius IV. He
rejected the Archbishopric of Cosenza offered by Pius IV in 1565,
leaving this position to his brother. From 1576 on he was moving
between Cosenza and Naples; in Naples he lived with the son and heir of
Alfonso Carafa, Ferrante, to whom he dedicated the final version of his
De rerum natura. He died in his hometown in 1588.

Telesio dedicated his whole life to establishing a new kind of
natural philosophy, which can be described as an early defense of
empiricism bound together with a rigorous criticism of Aristotelian
natural philosophy and Galenic physiology. Telesio blamed both
Aristotle and Galen for relying on elaborate reasoning rather than
sense perception and empirical research. His fervent attacks against
the greatest authorities of the Western philosophical and medical
traditions led Francis Bacon to speak of him as “the first of the
moderns” (Opera omnia vol. III, 1963, p. 114). He was
perhaps the most strident critic of metaphysics in late Renaissance
times. It was obviously due to his excellent relationships with popes
and clerics that he was not persecuted and was able during his own
lifetime to publish his rather heterodox writings, which went on the
index shortly after his death. His principal work is the aforementioned
De rerum natura iuxta propria principia (“On the Nature
of Things according to their Own Principles”), which in the last
augmented edition of the author's hand appeared in Naples in 1586. The
De rerum natura is a huge treatise in nine books which deals
with cosmology, biology, sense perception, reason and ethics. Another
treatise of major importance is Quod animal universum ab unica
animae substantia gubernatur. Contra Galenum, in which Telesio
critizised central conceptions of Galenic physiology and psychology.
This work was never printed, but circulated in manuscript copies (De
Franco, 1981, p. XXII). Smaller treatises deal with a variety of themes
such as colours, dreams, geology and meteorology, some of which were
published in Rome in 1565 (De iis quae in aere fiunt et de
terremotibus; De colorum generatione; De mari).
Telesio's philosophy was disseminated by friends and students such as
Tommaso Campanella, whose writings contain long paraphrases of
Telesian ideas; by Sertorio Quattromani, Telesio's successor as head of
the Accademia Cosentina, who published a synthesis of his predecessor's
philosophy in 1589; and by Antonio Persio, who gave lessons on
Telesio's thought in Venice and published a collection of smaller
works, the Varii de naturalibus rebus libelli, in 1590.
Giordano Bruno speaks of the “giudiciosissimo Telesio” in
the third dialog of De la causa, whilst Francis Bacon based
his own speculative philosophy of nature on a blend of Telesian and
Paracelsian conceptions (Giachetti Assenza 1980; Rees 1977; 1984).
Thomas Hobbes followed Telesio in the rejection of species (Schuhmann
1990; Leijenhorst 1998, p. 116ff.) The physiology of René
Descartes in De homine shows close similarities to Telesio's
physiological theories as they are presented in De natura
rerum (Hatfield 1992). Telesio also had some influence on Gassendi
and on libertine thinkers (Bianchi 1992).

Telesio's vision of the genesis of nature is simple to the point of
being archaic, yet at the same time astonishingly modern in the sense
that he seems to have been one of the very first defenders of a theory
of natural evolution without metaphysical or theological
presuppositions. According to his De rerum natura, the only
things which must be presupposed are passive matter and active force,
the latter of which Telesio thought of as twofold, heat and cold. These
principles were meant to replace the Aristotelian metaphysical
principles of matter and form. In order to explain how all natural
beings came into existence by these opposing forces, Telesio
presumed that in the beginning God had created two primary globes, the
sun and the earth, the sun being the seat of heat, the earth that of
coldness, and that He had separated them with such a distance in space
that they could not extinguish each other (DRN book I, ch. IV). All
natural things result from the battle of these antagonistic forces for
the possession of matter. The main region of that creative battle is
the surface of the earth, where they create metals, stones and animate
beings. The primary activity of warmth is to move fast and to dilate
and rarefy matter, whereas that of cold is to hinder movement and to
condense matter. Things differ according to the amount of heat or cold
they possess (and therefore according to their density and derivative
qualities such as velocity and colour). The quantity of matter is not
changed through the action of these forces upon it. The role of heat,
cold and matter as ‘natural principles’ had been highlighted
before by Girolamo Fracastoro in the first version of the
Homocentrica and in the dialogue Fracastorius sive De
anima (Lerner 1992), as well as by Girolamo Cardano in his
Liber unicus de natura.

Telesio's cosmology puts an end to metaphysical explanations.
Telesio thought space to be absolute (DRN book I, ch. XXV–XXVIII), thus
abolishing the Aristotelian notion of a bipartite cosmos divided into a
sublunary world, in which generation and corruption take place, and a
supralunary sphere with eternal regular movements. The existence of
vacuum within space is admitted, but things are said to have a natural
inclination to avoid empty space. In the cosmological chapters of book
IV Telesio critizised the Aristotelian explanation of the movement of
the sky by a transcendent telos, the God of Aristotle's metaphysics:
the sky doesn't move because of a desire for a being more perfect than
itself, but because it is its own nature to move and thus to sustain
its own life (DRN book IV, ch. XXIV; Aristotle, Metaph. XII,
ch. 6–7).

The things of nature are not created, governed and sustained by
divine providence. In Telesio's philosophy, there is no such thing as a
transcendent mind or idea. All things act solely according to their own
nature, starting from the primary forces of cold and heat. The
Epicurean chance is enclosed in Telesio's Stoic-influenced philosophy
of nature (Kessler 1992): everything can produce everything, an idea
which was soon to be sharply rejected by Francesco Patrizzi da Chierso,
one of the most important contemporary readers of Telesio
(“Obiectiones”, in the appendix of Telesio's Varii
libelli, p. 467 f.). In order to sustain themselves, these primary
forces and all beings which arise through their antagonistic
interaction must be able to sense themselves as well as the opposite
force, that is, they must sense what is convenient and what is
inconvenient or damaging for their survival and well-being. Sensation,
therefore, is not the property of embodied souls. Telesio's philosophy
can thus be described as a pansensism in the sense that all beings,
animate or inanimate, are said to have the power of sensation.

With regard to psychology, Telesio took a materialist standpoint.
According to his general rejection of the metaphysical (and therefore
inappropriate) principles of matter and form, he rejected Aristotle's
definition of the soul as forma corporis, i.e. as form and
entelechy of an organic body (Aristotle, De anima II,1).
According to Telesio, the soul is a separate being, but not in the
sense of the Platonists, who define it as an immortal essence acting as
the governor and mover of the body during its embodied life. Telesio
held the soul to be a specific part of the body, defining it as the
spiritus coursing through the nervous system and having its
main seat in the brain. The spiritus which overtakes the role
of the anima of the philosophical tradition is produced by the
white ‘semen’. Telesio calls it the spiritus e semine
eductus. He maintains in DRN book V, ch. I:

“This [separate substance] will therefore be the
spiritus, which took its origin from the semen, as we will
explain elsewhere (and it is to be found in all things made from semen,
namely those which are white and bloodless, with the exception of the
bones and similar things); and only the spirit is what perceives in the
animal, and moves sometimes with the whole body, sometimes with single
parts thereof, and solely governs the whole animal. That is to say, it
performs those actions which, according to the concurring opinion of
all, are typical of the soul.” (Vol. II, p. 208).

To ascribe psychic functions to a specific part of the body implies
a rejection of the difference between organic and inorganic life, which
dichotomy was central to the Aristotelian, Platonic and Christian
traditions. According to Telesio, there is a quantitative and not a
qualitative difference here, which consists in the higher degree of
complexity and the higher degree of warmth that some physical bodies
possess. Whereas metals or stones are homogenous bodies, organic bodies
consist of heterogeneous parts, including the bodily (though invisible)
spirit in the nerves and brain (DRN book V, ch. II). And just as there
is no metaphysical difference between living and non-living bodies,
there also does not exist a qualitative difference between animals and
humans—in both, it is the same spirit which coordinates the
functions and operations of the different bodily parts. In DRN book V,
ch. III Telesio states:

…and when it has been proved that in animals the
spirit produced from the semen is the substance of their soul, then one
cannot doubt that the same exists in humans, albeit in a much more
noble form, and it is surely not of a very different nature and does
not possess highly different capabilities. We see that humans are
formed by the same things as the other animals, and that they possess
the same abilities and even the same organs for feeding and
reproduction, and that they produce a very similar semen and eject it
in the same way and with the same pleasure and from a very similar part
and become tired after ejaculation, and that the same things are being
formed out of the semen in both cases, namely the same nervous and
membranous systems. And it is only [the spirit] which in all animate
beings is perceiving and moving in the same way and according to the
same dispositions. (Vol II, p. 216).

In order to explain how animate beings perform different functions
and operations, traditional psychological as well as physiological
theories referred to a threefold soul. Whereas Aristotle in De
anima had distinguished between the anima vegetativa,
anima sensitiva and anima cogitativa (which
distinction also corresponds to that of plants, animals and humans with
their specific faculties), Plato had established three parts of the
soul (Republic 434d-443e), which in the Timaios
(69aff.) he had associated with different organs, namely the rational
part of the soul (logistikon) to the brain, the spirited
(thumoeides) to the heart and the desirous or lower passions
(épithumêtikon) to the liver. In this
tripartition he was followed by the Stoic physician Galen (De
placitis Hippocratis et Platonis VII, I and III), who added a
threefold spirit—the spiritus naturalis being produced
in the liver, the spiritus vitalis refined in the blood and
the spiritus animalis distilled in the brain. Whereas the
Aristotelian psychology was combatted in the De rerum natura,
Telesio dedicated a whole treatise to the criticism of Galen, the
Quod animal universum ab unica animae substantia gubernatur. Contra
Galenum. According to Telesio, the functioning of an organic body
cannot be explained by presupposing a plurality of rulers. In asserting
the unity of the soul (i.e. spirit), Telesio followed the medical
theorist Giovanni Argenterio (1513–1572), who defended the unity of the
spirit against the Aristotelian and medical traditions.

Telesio combined the medical theory of spirit with a basically Stoic
notion, that of the hegemonikon, according to which the spirit
in the brain is responsible for all the states and operations
traditionally ascribed to the tripartite soul: “the animal
… is governed by one substance residing in the brain”
(Quod animal universum ch. XXV; Var. lib. p. 254). Whereas in
Quod animal universum he went on to explain the affects in
terms of physiology, in De rerum natura he added a theory of
sense perception and a theory of knowledge on physical grounds.

Telesio rejected the traditional concept of sense organs, replacing
it with a mechanistic explanation of sense perception (DRN books
V–VII). In his opinion, to speak of sense organs is inappropriate, as
the so-called sense organs are nothing else than “parts of the
body which are either more subtle or soft than others, or perforated
and open. One should not believe in the slightest that they are made
thus in order to offer some capacity or support of perceiving to the
sensitive soul (which seems to be the duty of organs), but in order to
provide an easy and open entry to the forces of external things and to
those things themselves.” (DRN book I, ch.VI; vol. I, p. 68).
What is perceived are not the forms or species of things as
the Aristotelians believed, but impulses of light and air (DRN book V,
ch. VIII; vol. II, 254; for the rejection of species see DRN
book VII, ch. XXX–XXXIII against the Aristotelian and ch. XVIII–XXIX
against the Galenic theory; Telesio's rejection of species was
taken up by Hobbes, Leviathan book I, ch. I “De
sensu”). As the sense of touch provides the most narrow contact
between outer object and sensing spirit, it assumes the role of the
primary sense, which was traditionally identified with the sense of
vision (DRN book VII, ch. IX, vol. III, p. 34.) The
informatio theory being rejected, Telesio comes close to a
neuronal explanation of sense perception, which is a mechanical process
arising from the transfer of tactile impressions through the nerves to
the brain. It is the spirit residing in the brain which experiences
nervous dilatations and contractions, and which judges these sensations
according to the basic scheme of pleasure and pain, giving out
corresponding reactions like moving towards something or avoiding
contact (DRN book VII ch. II–V). Strictly speaking, sense perception is
a sensation of sensing (sensus sensus) which takes place in
the brain: “Sense perception can only be the perception of the
activities of things and impulses in the air, and can only consist of
the perception of [the spirit's] own passions, transformations and
movements, particularly the latter. Indeed, the spirit perceives them
because he perceives that it is affected by them, that it is being
changed and moved.” (Vol. III, p. 6)

In his explanation of sense perception Telesio comes close to the
Democritan theory which he combines with the basic Stoic notion of
conservatio sui, a key term in Telesio's philosophy. Pleasure
is identified with the sensation of self-preservation, pain is the
sensation of destruction (DRN book VII, ch. III; vol. III, p. 10). In
this, as well as in his theory of knowledge, Telesio seems to follow
Girolamo Fracastoro's explanation of sense perception and understanding
given in the closing chapters of De sympathia et antipathia
rerum and in the epistemological treatise Turrius sive de
intellectione.

For Telesio, the conservatio sui is the foundation from
which all sensitive and cognitive functions arise. Defending an
empirical approach in epistemology, Telesio tried to annul the
traditional distinction between sense perception and reason, and he
denied that there exists something like a purely mental sphere and a
corresponding intellect which Aristotle in De anima III had
called nous. Understanding is a process which requires sense
perception and memory. According to Telesio, our memory is not visual.
What we remember are movements which our spirit has experienced and
given out when being in contact with external forces. If now the spirit
undergoes a similar experience, for example the pain of getting burned,
it will ascribe this perception to a similar or identical cause and
call it ‘fire’ (DRN book VIII, ch. 1; vol. III, p. 160). The
ability of making rational conclusions (ratiocinari) consists
in comparing new expierences to old ones and in supplementing hidden or
unknown aspects when refering them to former experiences. Telesio even
suggests replacing the term intelligere with
existimari and commemorari (DRN book VIII, ch. III;
vol. III, p. 164f.). Intellectual understanding therefore does not mean
to reach a realm of necessity and eternity, not even in mathematics,
which according to Telesio arises from sensual experience and is a
science of less dignity than the observation-based natural philosophy
(DRN book VIII, ch. IV; vol. III, p. 176f.).

The ethics exposed in the 9th book of De rerum
natura is strictly naturalist. The only objective which Telesio
ascribes to the spirit is self-preservation and self-improvement, the
former lying in its ability to react suitably to influences from the
external world, the latter in its capability of finding means to
improve its state of being. This comes about through theoretical
knowledge, specifically through natural philosophy and medicine (cf.
DRN book VIII, ch. XXI) and through learning to control one's own
emotions and desires. According to Telesio, we can voluntarily provoke
and suppress affections and their related actions (DRN book IX, ch. I;
vol. III, p. 332f.); what is more, we are able to master the degree to
which we desire and are affected (DRN book IX, ch. II; vol. III, p.
334). The principle of moral virtue is said to be a knowledge of what
is helpful and what is damaging for survival and well-being in human
society. All virtues and vices are reduced to self-conservation.

Whereas medieval and Renaissance authors often seemed to rely on the
double-truth theory in order to maintain the freedom of scientific
research and teaching, Telesio maintained a purely scientific approach.
But he did not deny the existence of God and of the human soul.
Telesio's God is not the God who acts in nature and history, though he
did not deny the possibility of miracles (DRN book IV, ch. XXV; vol. I,
p. 176). The God Telesio seems to imagine can be compared to a
mechanic. Just as the best mechanic creates an artefact which will work
without interruption and default, so the power of the almighty divine
artist is represented in a cosmos which is able to generate and to
sustain itself without ever running the danger of corruption (see DRN
book I, ch. X).

Besides the natural soul or spirit Telesio accepted the existence of
an immortal soul superimposed by God (DRN book V, ch. II–III). But in
his theory of psychology and ethics the soul does not play any
significant role, for which reason researchers have often held it to be
an addition designed to avoid conflicts with the Church. On the other
hand, there do exist certain modes of behavior which cannot be
explained in a purely naturalistic and materialistic way, such as the
human striving for eternity and the martyrs' denial of the highest
objective of self-preservation. Far from building a bridge to the
philosophical tradition, Telesio's definition of a second, divinely
superimposed soul as “forma corporis et praecipue spiritus”
deals a deathblow to Aristotle's teachings. According to Telesio, the
idea of an immortal soul was totally unknown to the heathen Aristotle,
who is severely criticized for confusing the concept of a natural
spirit with the religious idea of a soul (DRN book V, ch. II–III):

And when we have reproved Aristotle and will continue to
reprove him for having introduced the soul into the body as its
peculiar form, we have not condemned him and we will not condemn him
because he equated the soul created by God (a thing which one might
suspect was completely unknown to him) with the form of humans, but
rather because... he equated the soul which was generated from the
semen and which is the only one which senses, causes movements and is
(so to speak) something akin to the semen, with the form of the body.
(Vol. II, p. 218f.)

The SEP would like to congratulate the National Endowment for the Humanities on its 50th anniversary and express our indebtedness for the five generous grants it awarded our project from 1997 to 2007.
Readers who have benefited from the SEP are encouraged to examine the NEH’s anniversary page and, if inspired to do so, send a testimonial to neh50@neh.gov.